As a key staple crop, wheat is grown globally, with millions of farmers relying on it for their livelihoods. However, pest and weed issues remain a major challenge in wheat production, potentially leading to significant yield losses. To counter these challenges, farmers often turn to herbicides, as they are a cost-effective and efficient means of controlling weeds, which can reduce crop yields by competing for space, nutrients, and sunlight with the wheat plants. Unfortunately, using herbicides can cause unintended consequences, such as yellowing of wheat foliage, which can negatively impact yield outcomes.
Yellowing of wheat foliage is a common phenomenon that can occur following herbicide applications. The initial symptoms usually appear as yellowing of leaves, and in severe cases, necrosis of foliage. This effect is typically transient, with plants usually recovering within a few days to a few weeks. The yellowing of leaves can be attributed to the herbicide’s mode of action, which can interfere with the plant’s photosynthetic process. The yellowing may also be due to interference with the production of chlorophyll, which is essential for the plant’s photosynthesis to take place, and its colour is what makes the leaves appear green.
There are two primary ways herbicides can cause yellowing of wheat leaves. The first mechanism is due to the herbicide’s mode of action, which interferes with the plant’s metabolism. Selective herbicides target specific metabolic pathways of weeds but often have undesired effects on crops. This is because the herbicide may also affect the same metabolic pathways in the crop, leading to the yellowing of leaves. The second mechanism is when herbicides are applied during unfavourable weather conditions, such as high-temperature soil, hot and dry weather, or high humidity. These environmental factors can affect the herbicides’ absorption and efficacy, leading to an incomplete kill of the weeds and damaging the wheat foliage.
To avoid yellowing of wheat after herbicide application, farmers can take preventive measures such as choosing the right type of herbicide, timing the herbicide application when weather conditions favour its efficacy, and avoiding spraying during crop stress conditions such as drought. Also ensuring that the herbicide dose is within the recommended range, as over-application can cause herbicide damage.
In conclusion, herbicides remain an essential tool in managing weed challenges in wheat production, and their usage saves farmers an immense amount of money each year. However, farmers should remain cautious when applying herbicides to prevent potential yield losses. Yellowing of wheat foliage after an application of herbicides can significantly affect wheat outcomes, leading to yield losses; hence, farmers should aim to use herbicides safely to ensure they attain the best yields possible.